Genetic variability and forensic efficiency of 39 microsatellite loci in the Li ethnic group from Hainan Island in the South China Sea

Abstract

Background: Investigation of allele and genotype frequencies of microsatellite loci in various populations is an essential pre-requisite in forensic application.

Aim: The present study obtained population genetic data and forensic parameters of 39 autosomal Short Tandem Repeats (STRs) loci from a Chinese Li ethnic group and estimated the genetic relationships between Li and other reference populations.

Subjects and methods: Thirty-nine STR loci, which include D19S433, D5S818, D21S11, D18S51, D6S1043, D3S1358, D13S317, D7S820, D16S539, CSF1PO, Penta D, D2S441, vWA, D8S1179, TPOX, Penta E, TH01, D12S391, D2S1338, FGA, D6S477, D18S535, D19S253, D15S659, D11S2368, D20S470, D1S1656, D22-GATA198B05, D8S1132, D4S2366, D21S1270, D13S325, D9S925, D3S3045, D14S608, D10S1435, D7S3048, D17S1290 and D5S2500, were amplified in two multiplex DNA-STR fluorescence detection systems for 189 unrelated healthy individuals of the Chinese Li ethnic group. The allele frequency distribution and several parameters commonly used in forensic science were statistically analysed.

Results: A total of 378 alleles were observed with corresponding allelic frequencies ranging from 0.0026–0.5899. The power of discrimination and power of exclusion ranged from 0.7569–0.9672 and 0.2513–0.7355, respectively. The power of exclusion (PE) ranged from 0.2580–0.7943 for trio paternity cases and 0.1693–0.5940 for duo paternity cases. The polymorphism information content (PIC) ranged from 0.5001–0.8611. The cumulative match probability across these 39 loci was 2.4242?×?10^?38.

Conclusion: The results indicate that 39 STR loci are polymorphic among the Li ethnic group in Hainan Island in the South China Sea. This set of polymorphic STR loci provide highly polymorphic information and forensic efficiency for forensic individual identification and paternity testing, as well as basic population data for population genetics and anthropological research.     

Fluorescent quantitative PCR of Mycobacterium tuberculosis for differentiating intestinal tuberculosis from Crohn's disease

Intestinal tuberculosis (ITB) and Crohn''s disease (CD) are granulomatous disorders with similar clinical manifestations and pathological features that are often difficult to differentiate. This study evaluated the value of fluorescent quantitative polymerase chain reaction (FQ-PCR) for Mycobacterium tuberculosis (MTB) in fecal samples and biopsy specimens to differentiate ITB from CD. From June 2010 to March 2013, 86 consecutive patients (38 females and 48 males, median age 31.3 years) with provisional diagnoses of ITB and CD were recruited for the study. The patients'' clinical, endoscopic, and histological features were monitored until the final definite diagnoses were made. DNA was extracted from 250 mg fecal samples and biopsy tissues from each patient. The extracted DNA was amplified using FQ-PCR for the specific MTB sequence. A total of 29 ITB cases and 36 CD cases were included in the analysis. Perianal disease and longitudinal ulcers were significantly more common in the CD patients (P<0.05), whereas night sweats, ascites, and circumferential ulcers were significantly more common in the ITB patients (P<0.05). Fecal FQ-PCR for MTB was positive in 24 (82.8%) ITB patients and 3 (8.3%) CD patients. Tissue PCR was positive for MTB in 16 (55.2%) ITB patients and 2 (5.6%) CD patients. Compared with tissue FQ-PCR, fecal FQ-PCR was more sensitive (X²=5.16, P=0.02). We conclude that FQ-PCR for MTB on fecal and tissue samples is a valuable assay for differentiating ITB from CD, and fecal FQ-PCR has greater sensitivity for ITB than tissue FQ-PCR.     

Well-being and Its Influencing Factors of Junior High School Students from County Town and Rural Areas

目的 了解县城乡镇初中生幸福感水平及其影响因素.方法 采用Rosenberg自尊问卷、一般自我效能感量表和中学生应对方式问卷等对706名初中生进行调查.结果 觉得“很幸福”或“幸福”的学生占70.4％；女生的幸福感水平显著高于男生(x2=9.714,P＜0.01)；家庭经济状况较好的学生,幸福感水平较高(x2=58.184,P＜0.001)；幸福感水平年级间无显著差异(x2=0.471,P＞0.05)；自尊、自我效能感、问题解决、寻求社会支持、积极的合理化解释得分幸福组显著高于非幸福组(t1=9.257,t2=3.988,t3=4.245,t4=4.150,t5=5.184,P5＜0.001).忍耐、“幻想、否认”、逃避得分幸福组显著低于非幸福组(t1=-3.090,t2=-3.073,Ps＜0.01;t3=-3.830,P＜0.001).家庭经济状况、自尊、寻求社会支持、逃避应对方式能显著预测县城乡镇初中生的幸福感(x2=136.165,P＜0.001).结论 县城乡镇初中生总体上是幸福的,性别、家庭经济状况、自尊、自我效能感和应对方式等因素会影响其幸福感水平,并且家庭经济状况、自尊、寻求社会支持及逃避应对方式能有效预测其幸福感水平.